Catalog 50A-M_All_Low Res - TeeJet

Electric Regulating Valves
DirectoValve® Electric
Pressure Regulating Valves
The proper regulating valve will enhance
the operation of a sprayer, especially one
with an automatic rate controller. While
advanced electronics provide features
and control, the proper regulating valve
helps the system to respond quickly to
input changes and functions over a wide
range of application rates. Choosing the
proper valve involves determining the
maximum capacity required, the range
of application rates and the proper
motor speed.
System Capacity
A regulating valve’s system requirements
will depend on the application amount
and the pumping capacity. Additionally,
the regulating valve can be used in bypass
or throttling mode. In throttling mode,
the flow through the valve will be applied
through the nozzles. In bypass mode, the
excess flow from the pump is recirculated.
A valve that works well throughout the
flow spectrum has the best chance to
work in all situations.
Types of Regulating Valves
Special ball shapes make regulating valves
more responsive and able to work with
both high and low application rates.
Most agricultural sprayers use either a
% of Maximum Flow
Regulating Valve Flow Curves
100
90
80
70
60
50
40
30
20
10
0
PR Ball
RL Ball
R Ball
Butterfly
2-way ball valve or butterfly valve for
regulating purposes. When considering
sizing a regulating valve, the first concern
is to understand the valve’s flow curve
to determine how efficiently the valve
will regulate. Figure 1 shows typical flow
curves for DirectoValve® regulating type
valves. This will help to decide the type
of valve to use.
0 10 20 30 40 50 60 70 80 90 100
% of Travel
(Figure 1)
R Type Valve
Butterfly Valve
RL Valve
PR Valve
R Type and Butterfly Valves
As shown on the graph, the butterfly valve
has the most non-linear flow curve for final
1/3 (30°) of travel leading to an increase of 75%
in flow through the valve. The straight 2-
way “R” ball curve is not quite as steep, with
the flow through the valve increasing by
60% over the last 30° of travel. The “R” ball,
however, has the additional disadvantage
of not allowing significant flow during the
first 1/3 of its rotation. Since a small change
of rotation causes a significant change using
these valves, trying to regulate large flows
when the valve is two thirds to full open
presents a challenge.
RL Valve
Spraying Systems Co.® has developed a
special ball that allows the valve to start
regulating earlier thus extending the
regulating range. This special ball valve also
increases flow and the linear characteristic of
the valve during the first 3/4 of the valve cycle.
The flow from the valve starts 10º earlier,
than a regular R type ball and increases the
flow of the RL ball during the first 70% of
travel (Figure 1). The maximum capacity is
about 10% less than an R type valve.
Ball Type Regulating Valves
model number
344BR-2
344BR-3
344BRL-2
* 344BPR-2
* 344BPR-3
346BR-2
346BR-3
* 346BPR-2
* 346BPR-3
PR Valve
The PR valve uses a 3-way valve body and a
ball with a wedge removed. The combination
of this ball and a motor that rotates past
the standard 90º results in a valve with an
almost linear flow curve. The 2PR version has
one outlet plugged. The 3PR version allows
bypass flow to return to the tank.
As noted in Figure 1, the percentage of flow
increases by approximately the amount of ball
travel thus avoiding the rapid change seen
with standard ball valves and butterfly valves.
* Not available in stainless steel.
MAXIMUM PRESSURE
FLOW RATE AT A 5 PSI (0.34 bar)
PRESSURE DROP
300 PSI (20 bar) 32 GPM (121 l/min)
300 PSI (20 bar) 24 GPM (91 l/min)
300 PSI (20 bar) 27 GPM (102 l/min)
300 PSI (20 bar) 12 GPM (45 l/min)
300 PSI (20 bar) 12 GPM (45 l/min)
150 PSI (10 bar) 100 GPM (379 l/min)
150 PSI (10 bar) 64 GPM (242 l/min)
150 PSI (10 bar) 53 GPM (200 l/min)
150 PSI (10 bar) 53 GPM (200 l/min)
VALVES AND MANIFOLDS
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